Embodiments relate to a device, a tire pressure measurement system, a tire, a method and a computer program to obtain information indicating a tread depth of the tire.
The tread depth of car tires can be considered an important feature for safe driving, especially under wet, icy or changing road conditions. Moreover, a minimum tread depth is required by government regulations in most countries. When driving, the outer surface of the tire is continuously worn by friction and abrasion during the repetitive contacts with the road. So gradually, the tread depth reduces. The driver should be aware of the tread depth of his tires but this is not always the case.
The tread depth can be measured, for example, by sticking a measurement tool into the profile of a tire and reading the depth. Such readings are carried out manually and are therefore cumbersome to carry out; therefore, it may be considered challenging to frequently measure the tire tread depth manually. Tire Pressure Monitoring Systems (TPMS) may measure the tire tread depth indirectly by evaluating a signal of an acceleration sensor of the TPMS, when the tire hits the road and when the tire leaves it again, which however also has dependencies on temperature, tire pressure, road surface etc., and may therefore not always be reliable. Other concepts may use accelerations of a running tread or contact area of the tire to obtain information on the condition of the tire tread. The condition of the tire tread may further depend on the material thickness of the tire or contact area. Furthermore, acceleration measurements may make use of complex measurement circuits and actual accelerations may depend on further parameters such as the age and temperature of the rubber material of the tire, which may distort absolute results of acceleration measurements.
For tire tread measurements a mileage counter may be used in some vehicles. Such a concept may count a number of revolutions or rotations of a tire and estimate an overall mileage of the tire. The wear or use of a tire tread may also depend on other factors such as style of driving (accelerations, braking behavior, high speed portion, etc.) and condition of the road surface, which may render an estimation based on a mileage of tire imprecise.
Some concepts are introduced by documents DE 202 16 290 U1 2002 and U.S. Pat. No. 8,578,767 B2 2011.